1. Field of the Invention
This invention relates to a compression wrap for pneumatically applying dynamic pressure to the Achilles tendon.
2. Description of Related Art
Active people commonly experience the ache and debilitating effects of posterior heel pain as a result of three commonly accepted causes: Haglund syndrome, Achilles tendinitis/osis and Sever's disease.
Haglund syndrome is characterized by a painful soft tissue swelling where the Achilles tendon attaches to the calcaneum (heel bone). Haglund syndrome can often result in the development of a bony deposit on the back of the calcaneum or in the inflammation of the bursa, the fluid filled sac that decreases friction between the Achilles tendon and the calcaneum, which is known as retrocalcaneal bursitis. It is believed that Haglund syndrome results from the repetitive application of trauma or stress to the Achilles tendon.
Achilles tendinitis and tendinosis describe two classifications of tendon injury around the Achilles. Tendinosis refers to non-inflammatory intratendinous degeneration which is initially asymptomatic. Tendinitis describes symptomatic degeneration of the tendon associated with inflammation. Stanish has referred to these tendon classifications as non-union soft-tissue injuries. It is believed that non-union soft-tissue injuries are caused by inadequate perfusion of the local tissues. The affliction is characterized by soft tissue swelling, tenderness to the touch and roughening about the Achilles tendon known as crepitus. Those suffering from Achilles tendinitis/osis also experience pain with active pointing and passive raising of the foot.
Sever's disease results from a sclerosis or thickening and irregularity of the growth plate known as the calcaneal apophysis. It is believed that Sever's disease results from inflammation of the soft tissues of the heel following an injury. Sever's disease may cause a number of conditions including retrocalcaneal bursitis, traction apophysitis, which is the separating of the tendon from the bone, and osteochondrosis of the calcaneal apophysis which is irritation and inflammation of the bone and cartilage in the heel. Those suffering from Sever's disease experience pain down the back of the heel with passive raising of the foot, rapid and repetitive pointing of the foot and a springly gait. Sever's disease is aggravated by running and jumping.
These conditions are often treated by use of heel lifts which normally are foam pads approximately 0.25 inches thick; oral pain relievers; shoe inserts; anti-inflammatory medications; rest; ultrasound; various physical therapy treatments; and flexibility exercises. Surgical procedures such as diagonal removal of a heel bone known as oblique calcaneal osteotomy; removal of a deep and superficial retrocalcaneal bursae; cleaning and tendon repair are sometimes required for effective treatment.
U.S. Pat. No. 4,841,957 in the name of Wooten, et al. describes a U-shaped pad for applying compression around the affected area of the heel. However, the device disclosed in the Wooten patent only applies static pressure to the affected area of the Achilles tendon. We have reason to believe that a dynamic pulsating pressure would be more effective in remedying maladies associated with the Achilles tendon.
Nitric oxide is known to be released with a change in sheer stress in blood flow against the endothelial cells lining the veins. Our studies indicate that pulsating pressure accelerates venous velocity. Other studies show that acceleration of venous velocity increases sheer stress. A recent study, Modulation of Tendon Healing by Nitric Oxide, authored by George A. C. Murrell and others indicates that nitric oxide is present during tendon healing, and that the inhibition of nitric oxide reduces the healing response. While the tendons are avascular, the small nitric oxide molecule is known to pass through vessel walls. Nitric oxide acts as a vasodilator, providing greater fluid and nutrition to local tissues.
The results indicated by testing the present invention supports the belief that application of a dynamic, pulsating pressure around the sides of the Achilles tendon provides relief and healing to those suffering from maladies afflicting the Achilles tendon.
United Kingdom patent No. 817,521 discloses an apparatus for facilitating the blood circulation in the extremities of the human body. The device shown in this patent is cumbersome making the same difficult and time consuming to attach to the lower leg of the wearer. A further disadvantage in the use of this device resides in the fact that the inflatable cushions must be inflated from an external source, such as a pump.
U.S. Pat. No. 5,348,530 discloses a pneumatic ankle brace with a bladder and foot pump arrangement. The device of this patent is of rather complicated construction and requires use of a detachable hand-held pump.
U.S. Pat. No. 4,841,956 discloses a device adapted to be mounted to the lower leg and foot of a person for inducing venous blood flow in the leg. This device includes a pulse generator and programmable distributor necessitating a non-ambulatory position for the wearer during use.
U.S. Pat. No. 4,628,945 discloses a self-inflating ankle brace including air bags with resilient, compressible filler material. This patent discloses only a brace.